US-based Deep Isolation has completed a multi-year project with the UK Department for Energy Security & Net Zero (DESNZ) exploring the feasibility and commercial readiness of deep borehole disposal solutions for nuclear waste. The Energy Entrepreneurs Fund (EEF)-9001 project, monitored by DESNZ resulted in the manufacture of a first-of-its-kind disposal canister prototype.
The project was launched in December 2022 and in February Deep Isolation was awarded a grant DESNZ to develop a corrosion-resistant canister for the deep disposal of used nuclear fuel. The project was a collaboration between the UK Nuclear Advanced Manufacturing Research Centre (NAMRC), the University of Sheffield and US-based NAC International. It included the manufacture and testing of a prototype canister tailored to UK requirements and an assessment of the UK’s manufacturing supply chain capabilities. The canister had to ensure the safe encapsulation of used fuel assemblies in deep borehole repositories 1-3 km underground.
“This project is a game-changer for deep borehole disposal canisters,” said Deep Isolation CEO Rod Baltzer. “It not only validates key aspects of our technology but also advances manufacturability, cost efficiency, and supply chain readiness – paving the way for future deployments.”
A key outcome was the fabrication of two prototype canisters designed to encapsulate a pressurised water reactor (PWR) used fuel assembly for dry storage, transport, and final disposal. At the same time, Deep Isolation refined its performance models for long-term safety, leveraging corrosion resistance and post-closure gas migration studies, supported by data from a 2023 joint US Department of Energy-funded project (SAVANT – Sequential Advancement of Technology for Deep Borehole Disposal).
The SAVANT funding supported small-scale research and development of a universal canister design for used fuel and also assessed the capabilities of potential US-based suppliers of such a canister. Project activities were conducted at existing facilities of Deep Isolation (Santa Clara, CA and Atlanta, GA), SLB (Houston, TX); the Electric Power Research Institute (Charlotte, NC) and the independent non-profit Deep Borehole Demonstration Center Test Facility (Cameron, TX).
Charles Carpenter, Head of Research for UK AMRC’s Nuclear Manufacturing Group said the UK project “has demonstrated the manufacturability and scalability of Deep Isolation’s innovative canister design”. He added: “By collaborating with industry leaders, we’ve not only validated key technical aspects, but also identified pathways to strengthen the supply chain for advanced nuclear waste disposal solutions.”
The project elevated Deep Isolation’s technology readiness level (TRL) from TRL 3 to TRL 6, a significant milestone toward deployment. AMRC’s assessment of UK manufacturing capabilities identified supply chain challenges, particularly in sourcing the canister shell. The team proposed solutions to reduce manufacturing barriers, leading to projected cost reductions and a clearer pathway for future production at scale.
The performance feedback from the UK initiative informed an updated canister design, with the second prototype fabricated in early 2025 for additional testing. Deep Isolation said it will use this prototype to further demonstrate the safety and feasibility of its disposal solutions, strengthening industry confidence and regulatory acceptance.
